Merge pull request #178 from Lempireqc/master

AllowDelete

Author: JonathanMagnan

GraphDiff/GraphDiff/DbContextExtensions.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * This code is provided as is with no warranty. If you find a bug please report it on github.
  * If you would like to use the code please leave this comment at the top of the page
  * License MIT (c) Brent McKendrick 2012
@@ -12,23 +12,27 @@
 
 namespace RefactorThis.GraphDiff
 {
-	public static class DbContextExtensions
-	{
+    public static class DbContextExtensions
+    {
         /// <summary>
-        /// Merges a graph of entities with the data store.
+        ///     Merges a graph of entities with the data store.
         /// </summary>
         /// <typeparam name="T">The type of the root entity</typeparam>
         /// <param name="context">The database context to attach / detach.</param>
         /// <param name="entity">The root entity.</param>
         /// <param name="mapping">The mapping configuration to define the bounds of the graph</param>
+        /// <param name="allowDelete">NEED TEXTE!!!!</param>
         /// <returns>The attached entity graph</returns>
-	    public static T UpdateGraph<T>(this DbContext context, T entity, Expression<Func<IUpdateConfiguration<T>, object>> mapping = null) where T : class, new()
-	    {
+        public static T UpdateGraph<T>(this DbContext context, T entity,
+            Expression<Func<IUpdateConfiguration<T>, object>> mapping = null, bool allowDelete = true)
+            where T : class, new()
+        {
             var root = mapping == null ? new GraphNode() : new ConfigurationVisitor<T>().GetNodes(mapping);
+            root.AllowDelete = allowDelete;
             var graphDiffer = new GraphDiffer<T>(root);
             return graphDiffer.Merge(context, entity);
-	    }
+        }
 
         // TODO add IEnumerable<T> entities
-	}
+    }
 }

GraphDiff/GraphDiff/Internal/Graph/CollectionGraphNode.cs

@@ -46,10 +46,29 @@ public override void Update<T>(DbContext context, T existing, T entity)
                 }
             }
 
-            // remove obsolete items
-            foreach (var dbItem in dbHash.Values)
+            if (CheckAllowDelete(this))
             {
-                RemoveElement(context, dbItem, dbCollection);
+                // remove obsolete items
+                foreach (var dbItem in dbHash.Values)
+                {
+                    RemoveElement(context, dbItem, dbCollection);
+                }
+            }
+        }
+        
+        private static bool CheckAllowDelete(GraphNode node)
+        {
+            if (node.AllowDelete.HasValue)
+            {
+                return node.AllowDelete.Value;
+            }
+            else if (node.Parent != null)
+            {
+                return CheckAllowDelete(node.Parent);
+            }
+            else
+            {
+                return true;
             }
         }
 

GraphDiff/GraphDiff/Internal/Graph/GraphNode.cs

@@ -16,6 +16,7 @@ internal class GraphNode
 
         public GraphNode Parent { get; private set; }
         public Stack<GraphNode> Members { get; private set; }
+        public bool? AllowDelete { get; set; }
 
         protected readonly PropertyInfo Accessor;